I've never had your problem, but I've thought about what I would do if I did. The aluminum is probably stretched on one side, and to re-align the mast would take very careful, controlled bending in the opposite direction. Look down along the mast from one end to see if there is one particular spot that has a pronounced bend - most likely there is. To ensure that the mast does not crimp, because you will have to overflex the mast, you may want to build some sort of cradle to hold the mast that applies pressure on the opposite side where the bend is, something that helps the mast hold its curved shape. Affix one end and attach maybe a come-along to the other end - applying force very slowly. Flex it a bit and then release tension and check if any corrections were made. Then re-apply the force, going slightly further. Keep repeating the process until you either straighten the mast, kink it, or lose nerve. Other than that, I understand some ppl have replaced the top portion of their masts with composite tips for safety's sake (non-conductive of electricity), and I don't know how long they are, but maybe it would take care of some if not all of your problem.